It would reduce the problem, and I'm in favor of it. However, patent trolls would mutate and become outsourced "patent management" companies instead, litigating on behalf of the actual patent owners in exchange for a percentage. While some creators would be principled and refuse to try to profit this way, some would not be able to resist the lure.

It also still doesn't stop patents from being invented out of thin air without actually having to build something.

I don't think patents are salvageable. It's one thing to own the rights to a specific mystery novel, and another to own the concept of "the butler did it".